The class of work machines utilized for agricultural, industrial and other uses, termed as work machines, typically operates in a highly contaminated environment, thus making the function of cleaning air used by an air breathing internal combustion engine, especially important. Nowhere is this as important as in the agricultural field where the work machine is in a field harvesting crops which generates significant contaminants in the form of chaff and dust. It is necessary for such machines to have a pre-cleaner since the ambient level of contaminant is so significant. A filter alone would quickly become clogged.
In the present environment, pre-cleaners are employed upstream of the primary filter for the intake system of the engine. Such pre-cleaners take various forms, but as used commercially, are systems that impart a centrifugal motion to the air leading to the primary air filter inlet. Such centrifugal motion causes the denser contaminants to be thrown to the outer periphery of the pre-cleaner, leaving the less contaminated air to exit to the primary filter through a central inlet. Such air pre-cleaners have an outlet for the accumulated contaminants and some units have that outlet connected to an aspirator positioned in a muffler positioned in the engine exhaust system.
With the advent of environmental protection agency (EPA) emissions regulations applying to off highway work machines, it is become necessary to employ exhaust aftertreatment devices, including diesel particulate filters. Such devices require periodic burning of the accumulated soot particles to prevent clogging of the particulate filter. The process of cleaning such particles, commonly referred to as regeneration, causes a significant increase in the temperature of the exhaust, reaching levels as high as 600° C. This elevated temperature represents a potential problem in the contaminated environment of the work.
Accordingly, a need exists in the art to provide an effective and compact way of cooling the engine exhaust, at the same time providing a way of discarding contaminants collected in a pre-cleaner.